Abstract: A process for manufacturing caps, such as helmets, of reinforced resin, the reinforcement of which is comprised of a tricot or net-like material. The process comprises shaping the textile reinforcement, made of a plurality of layers of two or more textile caps to conform to the male component of a mold having complementary male and female components, inserting the male part, with the textile reinforcement, into the complementary female part of the mold, imparting a controlled tension to said textile reinforcement and injecting resin, in a liquid state, into the mold to envelope said textile reinforcement, and allowing said resin to solidify to thus obtain the cap, the reinforcement of which is enveloped in the resin in a state of tension. An impact resistant resin structure in the form of a cap is provided by said process.